This command sets how much more damage a hit from a zombie from behind will deal to you (i.e. if they hit your back). Default is 0, which means there is no extra damage. 0.5 would add 0.5x the dealt damage to the total (so 50% more damage).
The syntax for the z_hit_from_behind_factor command is as follows:
z_hit_from_behind_factor [multiplier] sv_cheats Default Value: 0
This command has the following arguments:
|Multiplier||The multiplier for the amount of damage that should be added to a zombie's attack when dealt from behind. This number is multiplied by the initial damage amount and added to the total. If you set this to 0.25 and a zombie dealt 10 damage usually, an attack from behind would deal 12.5 (because 10 * 0.25 is 2.5, 2.5 + 10 is 12.5).|
Find below working examples of the z_hit_from_behind_factor command.
This command would make it so that zombies deal an extra 50% damage when they attack you from behind.
This command would make damage dealt by zombies from behind be multiplied by 2.5 (150% more).